The protection of electrical installations of any type is fundamental to the safety of persons and property. In fact, an electrical fault frequently causes a fire, often with disastrous consequences. An electrical fault can also cause an electrification of sensitive areas or, more dramatically, the electrocution of persons.
Electrical protection applies to all types of electrical installations. This may notably include the electrical protection of buildings, industrial sites, aircraft and automobiles, for example. This may also notably include electrical protection on new electrical production infrastructures such as wind farms or arrays of photovoltaic panels. Other infrastructures also require electrical protection, for example electric vehicle charging stations.
In many cases, the effects produced by electrical faults are worsened by the lack of responsiveness of the power supply shut-off units. In fact, when electrical faults occur, there are still many situations in which the power supply shut-off unit is activated too late. Fault detection time is a very important parameter in the protection chain.
The shorter the time of response to the occurrence of an electrical fault, the greater the chances of preventing or at least limiting its effect.
Solutions are known for securing electrical installations. These solutions are essentially based on the analysis of electrical variables such as the current/voltage relationship. They have a plurality of disadvantages, these disadvantages being dependent on the application type.
A first disadvantage is the lack of responsiveness. Devices today represent a compromise between the quality of detection and the false alarm rate, some protection devices being able to allow some fifteen electric arcs to pass before taking the decision to open the circuit.
The response times of many existing systems are therefore too long. In particular, the diagnosis time is prolonged by the fact of having intermittent serial or parallel arc faults, since a plurality of iterations are required before taking the decision to secure a line.
For some applications, electrical networks have other constraints, notably as in the case of cable networks in airplanes. An avionic network requires a compact and lightweight redundant protection system, offering maximum reliability. Solutions exist for aeronautics, but the fact of making an airplane more and more electrical and the constraint of a protection solution per line, and therefore per load, result in increasingly bulky and therefore increasingly heavy electrical cores, notably due to the current sensors. These solutions are therefore not entirely satisfactory.
Cable networks inside motor vehicles have other requirements with regard to their protection. Protection systems in motor vehicles are currently limited to fuses. A new constraint in this field is notably due to the appearance of battery packs that are highly sensitive to short circuits with a risk of explosion. Voltage levels also tend to increase with a greater probability of having electric arc phenomena or intermittent faults causing serious consequences.
Other inherent characteristics of electrical installations require specific protection devices. In particular, the same device is not suitable for two alternating-current networks having different frequencies, or a direct-current network. Nor is a device for a direct-current network suitable for an alternating-current network.
Current solutions do not therefore allow the use of standard protection devices suitable for all applications, or at least the use of devices having a similar structure for all these applications. In economic terms, this lack of standardization does not enable production cost optimization.